Photoresponse of four D-A supramolecules derived from benzenecarboxylate donors and viologen acceptors

Donor-acceptor (D-A) photochromic materials have attracted extensive attention due to their broad application prospects. Herein, based on the viologen moiety (Bcbpy = 1-(4-carboxybenzyl)-4,4 '-bipyridinium) and different benzenecarboxylic acids (H3BTC = 1,3,5-benzenetricarboxylic acid; m-H3BTC = 1,2,4-benzenetricarboxylic acid; H4BTEC = 1,2,4,5-benzenetetracarboxylic acid; 1,4-H2NDC = 1,4-naphthalenedicarboxylic acid), four novel supramolecules have been prepared, namely (H2Bcbpy)(H2BTC)2 center dot(H3BTC)center dot H2O (1), (HBcbpy)(m-H2BTC)center dot 2H2O (2), (HBcbpy)(H2BTEC)0.5 center dot 3H2O (3), (HBcbpy)(1,4-HNDC) (4). The D-A system is formed by hydrogen bonding between the electron-deficient viologen acceptor and the electron-donating benzenecarboxylate donors. After UV irradiation, the photo-activated electrons can transfer from D to A in four compounds, exhibiting obvious photochromic behaviors. In addition, the photo-controlled fluorescence and the inkless and erasable printing capabilities are studied.

Automated summary

Four novel supramolecules based on viologen moiety and different benzenecarboxylic acids were synthesized. These materials exhibit obvious photochromic behaviors upon UV irradiation and possess photo-controlled fluorescence and inkless and erasable printing capabilities.